1. Field of the Invention
The present invention relates to a control system for monitoring vehicle maintenance conditions, and more particularly to the control system for integrally monitoring diagnosis informations of power units thereof.
2. Description of the Related Art
A power unit and other auxiliary systems of a vehicle are generally monitored by an on-board diagnosis apparatus. An engine is diagnosed by an on-board control unit with a self-diagnosis system on the following points; malfunctions of various actuators such as solenoid valves, driving motors and relays; malfunctions of various sensors such as an air flow sensor and a crank angle sensor; an existence of disconnections and short-circuits in electronic systems including input/output units such as various actuators, sensors, etc.; the existence of a leak in purge systems in which evaporating gas generated in a fuel tank is once adsorbed and stored in activated charcoal or the like packed in a canister and the evaporating gas in the canister is taken into and burnt in a combustion chamber through an intake passage under a preset engine condition so that the evaporating gas is prevented from being exhausted to the atmosphere; a malfunction of a thermostat used for a coolant recirculation system; the existence of an abnormality in a fuel system; a degradation of a catalyst for cleaning exhaust gases; the existence of the abnormality in an exhaust gas recirculation (EGR) system in which a portion of the exhaust gases is recirculated to the intake side for burning again; and the existence of a misfire in an ignition system. When any abnormal states are detected by the on-board diagnosis system based on the self-diagnosing system, a warning lamp or the like is lit up to send an alarm signal to a driver, thereby inspiring the driver to check and repair the vehicle in a dealer""s service factory. In the service factory, an external device, e.g., a trouble diagnosing device, is connected to an on-board electronic control unit for reading internal data, such as trouble location data and trouble data, from the on-board electronic control unit. Check and repair are then performed based on the read data.
One example of such a trouble diagnosing device is disclosed in Japanese Examined Patent Application Publication No. 7-15427 filed by the assignee of this application. The disclosed trouble diagnosing device is able to read the data in the on-board electronic control unit, i.e., detected signals from various sensors and switches, control signals outputted to various actuators such as fuel injectors, computation data within the system which are stored in the on-board electronic control unit, by utilizing the diagnosing device or by connecting a computer for an external expert system to the diagnosing device. As a result, it is possible to pursue the trouble location or the cause of trouble and to perform necessary repair or adjustment.
However, it has been conventional that, although the on-board diagnosis can detect a sign appearing before the occurrence of trouble due to, e.g., deterioration with time-dependent changes in parts and systems, the on-board diagnosis is utilized just for lighting up a warning lamp, for example, when the trouble has actually occurred under normal usage conditions. In the event of the trouble being actually occurred, the check and repair can be started only after reading out the diagnosis data with an external trouble diagnosing device. Furthermore, on that occasion, the trouble cause and the trouble location, including associated portions, are spread over a broad range in many cases. Therefore, a long time period is required to pursue the trouble causes, and increased is a burden imposed on both users and service factories in terms of time and cost.
Accordingly, it is an object of the present invention to provide a vehicle control system for an effective utilization of diagnosis informations of a power system mounted on a vehicle which can integrally execute diagnosing operations thereof and can give a beforehand notice of checked results before an occurrence of trouble in order to improve a system reliability.
In summary, the diagnosis informations of the power system is accumulated in an external database, and maintenance conditions of the vehicle are diagnosed on the basis of the diagnosis information accumulated with the vehicle control system of the present invention as described as above. Diagnosis results are distributed to a user of the vehicle and a person having an access right (authority) to the database. Accordingly, the notice given previously is given to the user before an abnormality actually occurs in the vehicle, whereby safety measures are secured. In addition, the diagnosis results are fed back to the person in order to reflect the results to development procedures for quality control departments and for engineering development departments and to contribute to an improvement of a total system reliability.
The other features and advantages of the present invention will be clearly understood from the following descriptions.